/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2013 Magister Solutions Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Sami Rantanen <sami.rantanen@magister.fi>
 */

#include "satellite-free-space-loss.h"

#include "satellite-const-variables.h"
#include "satellite-mobility-model.h"
#include "satellite-utils.h"

#include <ns3/double.h>
#include <ns3/log.h>
#include <ns3/string.h>

#include <cmath>
#include <stdint.h>

NS_LOG_COMPONENT_DEFINE("SatFreeSpaceLoss");

namespace ns3
{

NS_OBJECT_ENSURE_REGISTERED(SatFreeSpaceLoss);

TypeId
SatFreeSpaceLoss::GetTypeId(void)
{
    static TypeId tid =
        TypeId("ns3::SatFreeSpaceLoss").SetParent<Object>().AddConstructor<SatFreeSpaceLoss>();
    return tid;
}

SatFreeSpaceLoss::SatFreeSpaceLoss()
{
}

double
SatFreeSpaceLoss::GetFsldB(Ptr<MobilityModel> a, Ptr<MobilityModel> b, double frequencyHz) const
{
    NS_LOG_FUNCTION(this << frequencyHz);

    double fsl_dB;

    fsl_dB = SatUtils::LinearToDb(GetFsl(a, b, frequencyHz));

    return fsl_dB;
}

double
SatFreeSpaceLoss::GetFsl(Ptr<MobilityModel> a, Ptr<MobilityModel> b, double frequencyHz) const
{
    NS_LOG_FUNCTION(this << frequencyHz);

    double fsl;
    double distance =
        DynamicCast<SatMobilityModel>(a)->GetDistanceFrom(DynamicCast<SatMobilityModel>(b));

    fsl =
        std::pow(((4.0 * M_PI * distance * frequencyHz) / SatConstVariables::SPEED_OF_LIGHT), 2.0);

    return fsl;
}

} // namespace ns3
